Question

calcule valor de x em cada um.

a) 3x = 90
b) 2x +10 =70
c) 2x + 80=3x
d) x+50=3x+20

Answer 1

a) 3x=90
x=90=30
    3

b)2x+10=70
2x=70-10
2x=60
x=60=30
    2

c)2x+80=3x
2x-3x=-80
-x=-80
x=+80

d)x+50=3x+20
x-3x=20-50
-2x=-30
x=-30 = +15
    -2